Conventionally, a capillary electrophoresis apparatus has been used as an apparatus to analyze the density and amount of certain components contained in a specimen. In this capillary electrophoresis apparatus, after a migration solution has been filled into a capillary flow channel, a specimen is inserted at one end of the capillary flow channel. Next, by applying a voltage to electrodes that are provided at both ends of the capillary flow channel, electric current flows between the electrodes, and a certain component contained in the specimen moves to the other end of the capillary flow channel by the respective electrophoretic mobility. Due to this movement, the certain component of the specimen is separated from the other components, and by detecting the component using an optical method for example, the density and amount of the certain component can be analyzed.
Examples of capillary electrophoresis apparatuses are disclosed in Unexamined Japanese Patent Application KOKAI Publication No. 2007-107915 and Unexamined Japanese Patent Application KOKAI Publication No. H10-246721. In these electrophoresis apparatuses, whether or not migration solution has been filled in the capillary flow channel is constantly determined, so that after filling with migration solution, and before inserting the specimen, a voltage is applied to the electrodes on both ends of the capillary flow channel, and the value of the current flowing between the electrodes is measured.